The present invention relates to an edge light panel used on liquid crystal backlights for TV receiver sets and computers or edge light illuminators used for other backlighting purposes and a method of fabricating such an edge light panel.
For such edge light illuminators including liquid crystal backlights, use is made of an edge light panel for diffusely reflecting light from a primary light source mounted on the light-incident edge surface within the plane defined thereby for illumination and guiding the light in a certain direction within the plane.
Most generally used diffusing-reflection means are a given dot pattern screen-printed on a transparent substrate of acrylic resin, in which the dots are arranged in an equi-interval matrix array, as shown in JP-A-63-62104 filed by the inventors, in such a way that the dot percent is increased in a stepless manner as the dots are spaced away from the light source. This edge light panel is best suited for use on a liquid crystal backlight, because luminance and uniformity in particular are ensured.
However, the liquid crystal backlight using such an edge light panel is limited to monochromatic liquid crystal displays, and cannot be applied to multi-color liquid crystal displays, because they are required to have a considerably increased luminance.
Some improvement in luminance may be achieved by increasing the number of primary light sources used, for instance, by providing them in two upper and lower arrays. However, an increase in the number of primary light sources gives rise to an increase in the thickness of an edge light illuminator and an increase in power consumption as well. This is in sharp contrast to present design goals of fabricating portable TV receiver sets, computers and word processors to be reduced in thickness so as to be more compact and more efficient so as to reduce power consumption.
In view of such situations as mentioned above, an object of the invention is to provide an edge light panel that achieves a much higher luminance while maintaining a reduced thickness and uniformity in profile, and a method of fabricating such an edge light panel.